/*
 *  linux/arch/arm/kernel/ecard.c
 *
 *  Copyright 1995-2001 Russell King
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 *  Find all installed expansion cards, and handle interrupts from them.
 *
 *  Created from information from Acorns RiscOS3 PRMs
 *
 *  08-Dec-1996 RMK     Added code for the 9'th expansion card - the ether
 *                      podule slot.
 *  06-May-1997 RMK     Added blacklist for cards whose loader doesn't work.
 *  12-Sep-1997 RMK     Created new handling of interrupt enables/disables
 *                      - cards can now register their own routine to control
 *                      interrupts (recommended).
 *  29-Sep-1997 RMK     Expansion card interrupt hardware not being re-enabled
 *                      on reset from Linux. (Caused cards not to respond
 *                      under RiscOS without hard reset).
 *  15-Feb-1998 RMK     Added DMA support
 *  12-Sep-1998 RMK     Added EASI support
 *  10-Jan-1999 RMK     Run loaders in a simulated RISC OS environment.
 *  17-Apr-1999 RMK     Support for EASI Type C cycles.
 */
#define ECARD_C

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/sched.h>
#include <linux/interrupt.h>
#include <linux/completion.h>
#include <linux/reboot.h>
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <linux/device.h>
#include <linux/init.h>
#include <linux/mutex.h>
#include <linux/kthread.h>
#include <linux/io.h>

#include <asm/dma.h>
#include <asm/ecard.h>
#include <mach/hardware.h>
#include <asm/irq.h>
#include <asm/mmu_context.h>
#include <asm/mach/irq.h>
#include <asm/tlbflush.h>

#include "ecard.h"

#ifndef CONFIG_ARCH_RPC
#define HAVE_EXPMASK
#endif

struct ecard_request {
        void            (*fn)(struct ecard_request *);
        ecard_t         *ec;
        unsigned int    address;
        unsigned int    length;
        unsigned int    use_loader;
        void            *buffer;
        struct completion *complete;
};

struct expcard_blacklist {
        unsigned short   manufacturer;
        unsigned short   product;
        const char      *type;
};

static ecard_t *cards;
static ecard_t *slot_to_expcard[MAX_ECARDS];
static unsigned int ectcr;
#ifdef HAS_EXPMASK
static unsigned int have_expmask;
#endif

/* List of descriptions of cards which don't have an extended
 * identification, or chunk directories containing a description.
 */
static struct expcard_blacklist __initdata blacklist[] = {
        { MANU_ACORN, PROD_ACORN_ETHER1, "Acorn Ether1" }
};

asmlinkage extern int
ecard_loader_reset(unsigned long base, loader_t loader);
asmlinkage extern int
ecard_loader_read(int off, unsigned long base, loader_t loader);

static inline unsigned short ecard_getu16(unsigned char *v)
{
        return v[0] | v[1] << 8;
}

static inline signed long ecard_gets24(unsigned char *v)
{
        return v[0] | v[1] << 8 | v[2] << 16 | ((v[2] & 0x80) ? 0xff000000 : 0);
}

static inline ecard_t *slot_to_ecard(unsigned int slot)
{
        return slot < MAX_ECARDS ? slot_to_expcard[slot] : NULL;
}

/* ===================== Expansion card daemon ======================== */
/*
 * Since the loader programs on the expansion cards need to be run
 * in a specific environment, create a separate task with this
 * environment up, and pass requests to this task as and when we
 * need to.
 *
 * This should allow 99% of loaders to be called from Linux.
 *
 * From a security standpoint, we trust the card vendors.  This
 * may be a misplaced trust.
 */
static void ecard_task_reset(struct ecard_request *req)
{
        struct expansion_card *ec = req->ec;
        struct resource *res;

        res = ec->slot_no == 8
                ? &ec->resource[ECARD_RES_MEMC]
                : ec->easi
                  ? &ec->resource[ECARD_RES_EASI]
                  : &ec->resource[ECARD_RES_IOCSYNC];

        ecard_loader_reset(res->start, ec->loader);
}

static void ecard_task_readbytes(struct ecard_request *req)
{
        struct expansion_card *ec = req->ec;
        unsigned char *buf = req->buffer;
        unsigned int len = req->length;
        unsigned int off = req->address;

        if (ec->slot_no == 8) {
                void __iomem *base = (void __iomem *)
                                ec->resource[ECARD_RES_MEMC].start;

                /*
                 * The card maintains an index which increments the address
                 * into a 4096-byte page on each access.  We need to keep
                 * track of the counter.
                 */
                static unsigned int index;
                unsigned int page;

                page = (off >> 12) * 4;
                if (page > 256 * 4)
                        return;

                off &= 4095;

                /*
                 * If we are reading offset 0, or our current index is
                 * greater than the offset, reset the hardware index counter.
                 */
                if (off == 0 || index > off) {
                        writeb(0, base);
                        index = 0;
                }

                /*
                 * Increment the hardware index counter until we get to the
                 * required offset.  The read bytes are discarded.
                 */
                while (index < off) {
                        readb(base + page);
                        index += 1;
                }

                while (len--) {
                        *buf++ = readb(base + page);
                        index += 1;
                }
        } else {
                unsigned long base = (ec->easi
                         ? &ec->resource[ECARD_RES_EASI]
                         : &ec->resource[ECARD_RES_IOCSYNC])->start;
                void __iomem *pbase = (void __iomem *)base;

                if (!req->use_loader || !ec->loader) {
                        off *= 4;
                        while (len--) {
                                *buf++ = readb(pbase + off);
                                off += 4;
                        }
                } else {
                        while(len--) {
                                /*
                                 * The following is required by some
                                 * expansion card loader programs.
                                 */
                                *(unsigned long *)0x108 = 0;
                                *buf++ = ecard_loader_read(off++, base,
                                                           ec->loader);
                        }
                }
        }

}

static DECLARE_WAIT_QUEUE_HEAD(ecard_wait);
static struct ecard_request *ecard_req;
static DEFINE_MUTEX(ecard_mutex);

/*
 * Set up the expansion card daemon's page tables.
 */
static void ecard_init_pgtables(struct mm_struct *mm)
{
        struct vm_area_struct vma;

        /* We want to set up the page tables for the following mapping:
         *  Virtual     Physical
         *  0x03000000  0x03000000
         *  0x03010000  unmapped
         *  0x03210000  0x03210000
         *  0x03400000  unmapped
         *  0x08000000  0x08000000
         *  0x10000000  unmapped
         *
         * FIXME: we don't follow this 100% yet.
         */
        pgd_t *src_pgd, *dst_pgd;

        src_pgd = pgd_offset(mm, (unsigned long)IO_BASE);
        dst_pgd = pgd_offset(mm, IO_START);

        memcpy(dst_pgd, src_pgd, sizeof(pgd_t) * (IO_SIZE / PGDIR_SIZE));

        src_pgd = pgd_offset(mm, EASI_BASE);
        dst_pgd = pgd_offset(mm, EASI_START);

        memcpy(dst_pgd, src_pgd, sizeof(pgd_t) * (EASI_SIZE / PGDIR_SIZE));

        vma.vm_mm = mm;

        flush_tlb_range(&vma, IO_START, IO_START + IO_SIZE);
        flush_tlb_range(&vma, EASI_START, EASI_START + EASI_SIZE);
}

static int ecard_init_mm(void)
{
        struct mm_struct * mm = mm_alloc();
        struct mm_struct *active_mm = current->active_mm;

        if (!mm)
                return -ENOMEM;

        current->mm = mm;
        current->active_mm = mm;
        activate_mm(active_mm, mm);
        mmdrop(active_mm);
        ecard_init_pgtables(mm);
        return 0;
}

static int
ecard_task(void * unused)
{
        /*
         * Allocate a mm.  We're not a lazy-TLB kernel task since we need
         * to set page table entries where the user space would be.  Note
         * that this also creates the page tables.  Failure is not an
         * option here.
         */
        if (ecard_init_mm())
                panic("kecardd: unable to alloc mm\n");

        while (1) {
                struct ecard_request *req;

                wait_event_interruptible(ecard_wait, ecard_req != NULL);

                req = xchg(&ecard_req, NULL);
                if (req != NULL) {
                        req->fn(req);
                        complete(req->complete);
                }
        }
}

/*
 * Wake the expansion card daemon to action our request.
 *
 * FIXME: The test here is not sufficient to detect if the
 * kcardd is running.
 */
static void ecard_call(struct ecard_request *req)
{
        DECLARE_COMPLETION_ONSTACK(completion);

        req->complete = &completion;

        mutex_lock(&ecard_mutex);
        ecard_req = req;
        wake_up(&ecard_wait);

        /*
         * Now wait for kecardd to run.
         */
        wait_for_completion(&completion);
        mutex_unlock(&ecard_mutex);
}

/* ======================= Mid-level card control ===================== */

static void
ecard_readbytes(void *addr, ecard_t *ec, int off, int len, int useld)
{
        struct ecard_request req;

        req.fn          = ecard_task_readbytes;
        req.ec          = ec;
        req.address     = off;
        req.length      = len;
        req.use_loader  = useld;
        req.buffer      = addr;

        ecard_call(&req);
}

int ecard_readchunk(struct in_chunk_dir *cd, ecard_t *ec, int id, int num)
{
        struct ex_chunk_dir excd;
        int index = 16;
        int useld = 0;

        if (!ec->cid.cd)
                return 0;

        while(1) {
                ecard_readbytes(&excd, ec, index, 8, useld);
                index += 8;
                if (c_id(&excd) == 0) {
                        if (!useld && ec->loader) {
                                useld = 1;
                                index = 0;
                                continue;
                        }
                        return 0;
                }
                if (c_id(&excd) == 0xf0) { /* link */
                        index = c_start(&excd);
                        continue;
                }
                if (c_id(&excd) == 0x80) { /* loader */
                        if (!ec->loader) {
                                ec->loader = kmalloc(c_len(&excd),
                                                               GFP_KERNEL);
                                if (ec->loader)
                                        ecard_readbytes(ec->loader, ec,
                                                        (int)c_start(&excd),
                                                        c_len(&excd), useld);
                                else
                                        return 0;
                        }
                        continue;
                }
                if (c_id(&excd) == id && num-- == 0)
                        break;
        }

        if (c_id(&excd) & 0x80) {
                switch (c_id(&excd) & 0x70) {
                case 0x70:
                        ecard_readbytes((unsigned char *)excd.d.string, ec,
                                        (int)c_start(&excd), c_len(&excd),
                                        useld);
                        break;
                case 0x00:
                        break;
                }
        }
        cd->start_offset = c_start(&excd);
        memcpy(cd->d.string, excd.d.string, 256);
        return 1;
}

/* ======================= Interrupt control ============================ */

static void ecard_def_irq_enable(ecard_t *ec, int irqnr)
{
#ifdef HAS_EXPMASK
        if (irqnr < 4 && have_expmask) {
                have_expmask |= 1 << irqnr;
                __raw_writeb(have_expmask, EXPMASK_ENABLE);
        }
#endif
}

static void ecard_def_irq_disable(ecard_t *ec, int irqnr)
{
#ifdef HAS_EXPMASK
        if (irqnr < 4 && have_expmask) {
                have_expmask &= ~(1 << irqnr);
                __raw_writeb(have_expmask, EXPMASK_ENABLE);
        }
#endif
}

static int ecard_def_irq_pending(ecard_t *ec)
{
        return !ec->irqmask || readb(ec->irqaddr) & ec->irqmask;
}

static void ecard_def_fiq_enable(ecard_t *ec, int fiqnr)
{
        panic("ecard_def_fiq_enable called - impossible");
}

static void ecard_def_fiq_disable(ecard_t *ec, int fiqnr)
{
        panic("ecard_def_fiq_disable called - impossible");
}

static int ecard_def_fiq_pending(ecard_t *ec)
{
        return !ec->fiqmask || readb(ec->fiqaddr) & ec->fiqmask;
}

static expansioncard_ops_t ecard_default_ops = {
        ecard_def_irq_enable,
        ecard_def_irq_disable,
        ecard_def_irq_pending,
        ecard_def_fiq_enable,
        ecard_def_fiq_disable,
        ecard_def_fiq_pending
};

/*
 * Enable and disable interrupts from expansion cards.
 * (interrupts are disabled for these functions).
 *
 * They are not meant to be called directly, but via enable/disable_irq.
 */
static void ecard_irq_unmask(struct irq_data *d)
{
        ecard_t *ec = slot_to_ecard(d->irq - 32);

        if (ec) {
                if (!ec->ops)
                        ec->ops = &ecard_default_ops;

                if (ec->claimed && ec->ops->irqenable)
                        ec->ops->irqenable(ec, d->irq);
                else
                        printk(KERN_ERR "ecard: rejecting request to "
                                "enable IRQs for %d\n", d->irq);
        }
}

static void ecard_irq_mask(struct irq_data *d)
{
        ecard_t *ec = slot_to_ecard(d->irq - 32);

        if (ec) {
                if (!ec->ops)
                        ec->ops = &ecard_default_ops;

                if (ec->ops && ec->ops->irqdisable)
                        ec->ops->irqdisable(ec, d->irq);
        }
}

static struct irq_chip ecard_chip = {
        .name           = "ECARD",
        .irq_ack        = ecard_irq_mask,
        .irq_mask       = ecard_irq_mask,
        .irq_unmask     = ecard_irq_unmask,
};

void ecard_enablefiq(unsigned int fiqnr)
{
        ecard_t *ec = slot_to_ecard(fiqnr);

        if (ec) {
                if (!ec->ops)
                        ec->ops = &ecard_default_ops;

                if (ec->claimed && ec->ops->fiqenable)
                        ec->ops->fiqenable(ec, fiqnr);
                else
                        printk(KERN_ERR "ecard: rejecting request to "
                                "enable FIQs for %d\n", fiqnr);
        }
}

void ecard_disablefiq(unsigned int fiqnr)
{
        ecard_t *ec = slot_to_ecard(fiqnr);

        if (ec) {
                if (!ec->ops)
                        ec->ops = &ecard_default_ops;

                if (ec->ops->fiqdisable)
                        ec->ops->fiqdisable(ec, fiqnr);
        }
}

static void ecard_dump_irq_state(void)
{
        ecard_t *ec;

        printk("Expansion card IRQ state:\n");

        for (ec = cards; ec; ec = ec->next) {
                if (ec->slot_no == 8)
                        continue;

                printk("  %d: %sclaimed, ",
                       ec->slot_no, ec->claimed ? "" : "not ");

                if (ec->ops && ec->ops->irqpending &&
                    ec->ops != &ecard_default_ops)
                        printk("irq %spending\n",
                               ec->ops->irqpending(ec) ? "" : "not ");
                else
                        printk("irqaddr %p, mask = %02X, status = %02X\n",
                               ec->irqaddr, ec->irqmask, readb(ec->irqaddr));
        }
}

static void ecard_check_lockup(struct irq_desc *desc)
{
        static unsigned long last;
        static int lockup;

        /*
         * If the timer interrupt has not run since the last million
         * unrecognised expansion card interrupts, then there is
         * something seriously wrong.  Disable the expansion card
         * interrupts so at least we can continue.
         *
         * Maybe we ought to start a timer to re-enable them some time
         * later?
         */
        if (last == jiffies) {
                lockup += 1;
                if (lockup > 1000000) {
                        printk(KERN_ERR "\nInterrupt lockup detected - "
                               "disabling all expansion card interrupts\n");

                        desc->irq_data.chip->irq_mask(&desc->irq_data);
                        ecard_dump_irq_state();
                }
        } else
                lockup = 0;

        /*
         * If we did not recognise the source of this interrupt,
         * warn the user, but don't flood the user with these messages.
         */
        if (!last || time_after(jiffies, last + 5*HZ)) {
                last = jiffies;
                printk(KERN_WARNING "Unrecognised interrupt from backplane\n");
                ecard_dump_irq_state();
        }
}

static void
ecard_irq_handler(unsigned int irq, struct irq_desc *desc)
{
        ecard_t *ec;
        int called = 0;

        desc->irq_data.chip->irq_mask(&desc->irq_data);
        for (ec = cards; ec; ec = ec->next) {
                int pending;

                if (!ec->claimed || ec->irq == NO_IRQ || ec->slot_no == 8)
                        continue;

                if (ec->ops && ec->ops->irqpending)
                        pending = ec->ops->irqpending(ec);
                else
                        pending = ecard_default_ops.irqpending(ec);

                if (pending) {
                        generic_handle_irq(ec->irq);
                        called ++;
                }
        }
        desc->irq_data.chip->irq_unmask(&desc->irq_data);

        if (called == 0)
                ecard_check_lockup(desc);
}

#ifdef HAS_EXPMASK
static unsigned char priority_masks[] =
{
        0xf0, 0xf1, 0xf3, 0xf7, 0xff, 0xff, 0xff, 0xff
};

static unsigned char first_set[] =
{
        0x00, 0x00, 0x01, 0x00, 0x02, 0x00, 0x01, 0x00,
        0x03, 0x00, 0x01, 0x00, 0x02, 0x00, 0x01, 0x00
};

static void
ecard_irqexp_handler(unsigned int irq, struct irq_desc *desc)
{
        const unsigned int statusmask = 15;
        unsigned int status;

        status = __raw_readb(EXPMASK_STATUS) & statusmask;
        if (status) {
                unsigned int slot = first_set[status];
                ecard_t *ec = slot_to_ecard(slot);

                if (ec->claimed) {
                        /*
                         * this ugly code is so that we can operate a
                         * prioritorising system:
                         *
                         * Card 0       highest priority
                         * Card 1
                         * Card 2
                         * Card 3       lowest priority
                         *
                         * Serial cards should go in 0/1, ethernet/scsi in 2/3
                         * otherwise you will lose serial data at high speeds!
                         */
                        generic_handle_irq(ec->irq);
                } else {
                        printk(KERN_WARNING "card%d: interrupt from unclaimed "
                               "card???\n", slot);
                        have_expmask &= ~(1 << slot);
                        __raw_writeb(have_expmask, EXPMASK_ENABLE);
                }
        } else
                printk(KERN_WARNING "Wild interrupt from backplane (masks)\n");
}

static int __init ecard_probeirqhw(void)
{
        ecard_t *ec;
        int found;

        __raw_writeb(0x00, EXPMASK_ENABLE);
        __raw_writeb(0xff, EXPMASK_STATUS);
        found = (__raw_readb(EXPMASK_STATUS) & 15) == 0;
        __raw_writeb(0xff, EXPMASK_ENABLE);

        if (found) {
                printk(KERN_DEBUG "Expansion card interrupt "
                       "management hardware found\n");

                /* for each card present, set a bit to '1' */
                have_expmask = 0x80000000;

                for (ec = cards; ec; ec = ec->next)
                        have_expmask |= 1 << ec->slot_no;

                __raw_writeb(have_expmask, EXPMASK_ENABLE);
        }

        return found;
}
#else
#define ecard_irqexp_handler NULL
#define ecard_probeirqhw() (0)
#endif

#ifndef IO_EC_MEMC8_BASE
#define IO_EC_MEMC8_BASE 0
#endif

static unsigned int __ecard_address(ecard_t *ec, card_type_t type, card_speed_t speed)
{
        unsigned long address = 0;
        int slot = ec->slot_no;

        if (ec->slot_no == 8)
                return IO_EC_MEMC8_BASE;

        ectcr &= ~(1 << slot);

        switch (type) {
        case ECARD_MEMC:
                if (slot < 4)
                        address = IO_EC_MEMC_BASE + (slot << 12);
                break;

        case ECARD_IOC:
                if (slot < 4)
                        address = IO_EC_IOC_BASE + (slot << 12);
#ifdef IO_EC_IOC4_BASE
                else
                        address = IO_EC_IOC4_BASE + ((slot - 4) << 12);
#endif
                if (address)
                        address +=  speed << 17;
                break;

#ifdef IO_EC_EASI_BASE
        case ECARD_EASI:
                address = IO_EC_EASI_BASE + (slot << 22);
                if (speed == ECARD_FAST)
                        ectcr |= 1 << slot;
                break;
#endif
        default:
                break;
        }

#ifdef IOMD_ECTCR
        iomd_writeb(ectcr, IOMD_ECTCR);
#endif
        return address;
}

static int ecard_prints(struct seq_file *m, ecard_t *ec)
{
        seq_printf(m, "  %d: %s ", ec->slot_no, ec->easi ? "EASI" : "    ");

        if (ec->cid.id == 0) {
                struct in_chunk_dir incd;

                seq_printf(m, "[%04X:%04X] ",
                        ec->cid.manufacturer, ec->cid.product);

                if (!ec->card_desc && ec->cid.cd &&
                    ecard_readchunk(&incd, ec, 0xf5, 0)) {
                        ec->card_desc = kmalloc(strlen(incd.d.string)+1, GFP_KERNEL);

                        if (ec->card_desc)
                                strcpy((char *)ec->card_desc, incd.d.string);
                }

                seq_printf(m, "%s\n", ec->card_desc ? ec->card_desc : "*unknown*");
        } else
                seq_printf(m, "Simple card %d\n", ec->cid.id);

        return 0;
}

static int ecard_devices_proc_show(struct seq_file *m, void *v)
{
        ecard_t *ec = cards;

        while (ec) {
                ecard_prints(m, ec);
                ec = ec->next;
        }
        return 0;
}

static int ecard_devices_proc_open(struct inode *inode, struct file *file)
{
        return single_open(file, ecard_devices_proc_show, NULL);
}

static const struct file_operations bus_ecard_proc_fops = {
        .owner          = THIS_MODULE,
        .open           = ecard_devices_proc_open,
        .read           = seq_read,
        .llseek         = seq_lseek,
        .release        = single_release,
};

static struct proc_dir_entry *proc_bus_ecard_dir = NULL;

static void ecard_proc_init(void)
{
        proc_bus_ecard_dir = proc_mkdir("bus/ecard", NULL);
        proc_create("devices", 0, proc_bus_ecard_dir, &bus_ecard_proc_fops);
}

#define ec_set_resource(ec,nr,st,sz)                            \
        do {                                                    \
                (ec)->resource[nr].name = dev_name(&ec->dev);   \
                (ec)->resource[nr].start = st;                  \
                (ec)->resource[nr].end = (st) + (sz) - 1;       \
                (ec)->resource[nr].flags = IORESOURCE_MEM;      \
        } while (0)

static void __init ecard_free_card(struct expansion_card *ec)
{
        int i;

        for (i = 0; i < ECARD_NUM_RESOURCES; i++)
                if (ec->resource[i].flags)
                        release_resource(&ec->resource[i]);

        kfree(ec);
}

static struct expansion_card *__init ecard_alloc_card(int type, int slot)
{
        struct expansion_card *ec;
        unsigned long base;
        int i;

        ec = kzalloc(sizeof(ecard_t), GFP_KERNEL);
        if (!ec) {
                ec = ERR_PTR(-ENOMEM);
                goto nomem;
        }

        ec->slot_no = slot;
        ec->easi = type == ECARD_EASI;
        ec->irq = NO_IRQ;
        ec->fiq = NO_IRQ;
        ec->dma = NO_DMA;
        ec->ops = &ecard_default_ops;

        dev_set_name(&ec->dev, "ecard%d", slot);
        ec->dev.parent = NULL;
        ec->dev.bus = &ecard_bus_type;
        ec->dev.dma_mask = &ec->dma_mask;
        ec->dma_mask = (u64)0xffffffff;
        ec->dev.coherent_dma_mask = ec->dma_mask;

        if (slot < 4) {
                ec_set_resource(ec, ECARD_RES_MEMC,
                                PODSLOT_MEMC_BASE + (slot << 14),
                                PODSLOT_MEMC_SIZE);
                base = PODSLOT_IOC0_BASE + (slot << 14);
        } else
                base = PODSLOT_IOC4_BASE + ((slot - 4) << 14);

#ifdef CONFIG_ARCH_RPC
        if (slot < 8) {
                ec_set_resource(ec, ECARD_RES_EASI,
                                PODSLOT_EASI_BASE + (slot << 24),
                                PODSLOT_EASI_SIZE);
        }

        if (slot == 8) {
                ec_set_resource(ec, ECARD_RES_MEMC, NETSLOT_BASE, NETSLOT_SIZE);
        } else
#endif

        for (i = 0; i <= ECARD_RES_IOCSYNC - ECARD_RES_IOCSLOW; i++)
                ec_set_resource(ec, i + ECARD_RES_IOCSLOW,
                                base + (i << 19), PODSLOT_IOC_SIZE);

        for (i = 0; i < ECARD_NUM_RESOURCES; i++) {
                if (ec->resource[i].flags &&
                    request_resource(&iomem_resource, &ec->resource[i])) {
                        dev_err(&ec->dev, "resource(s) not available\n");
                        ec->resource[i].end -= ec->resource[i].start;
                        ec->resource[i].start = 0;
                        ec->resource[i].flags = 0;
                }
        }

 nomem:
        return ec;
}

static ssize_t ecard_show_irq(struct device *dev, struct device_attribute *attr, char *buf)
{
        struct expansion_card *ec = ECARD_DEV(dev);
        return sprintf(buf, "%u\n", ec->irq);
}

static ssize_t ecard_show_dma(struct device *dev, struct device_attribute *attr, char *buf)
{
        struct expansion_card *ec = ECARD_DEV(dev);
        return sprintf(buf, "%u\n", ec->dma);
}

static ssize_t ecard_show_resources(struct device *dev, struct device_attribute *attr, char *buf)
{
        struct expansion_card *ec = ECARD_DEV(dev);
        char *str = buf;
        int i;

        for (i = 0; i < ECARD_NUM_RESOURCES; i++)
                str += sprintf(str, "%08x %08x %08lx\n",
                                ec->resource[i].start,
                                ec->resource[i].end,
                                ec->resource[i].flags);

        return str - buf;
}

static ssize_t ecard_show_vendor(struct device *dev, struct device_attribute *attr, char *buf)
{
        struct expansion_card *ec = ECARD_DEV(dev);
        return sprintf(buf, "%u\n", ec->cid.manufacturer);
}

static ssize_t ecard_show_device(struct device *dev, struct device_attribute *attr, char *buf)
{
        struct expansion_card *ec = ECARD_DEV(dev);
        return sprintf(buf, "%u\n", ec->cid.product);
}

static ssize_t ecard_show_type(struct device *dev, struct device_attribute *attr, char *buf)
{
        struct expansion_card *ec = ECARD_DEV(dev);
        return sprintf(buf, "%s\n", ec->easi ? "EASI" : "IOC");
}

static struct device_attribute ecard_dev_attrs[] = {
        __ATTR(device,   S_IRUGO, ecard_show_device,    NULL),
        __ATTR(dma,      S_IRUGO, ecard_show_dma,       NULL),
        __ATTR(irq,      S_IRUGO, ecard_show_irq,       NULL),
        __ATTR(resource, S_IRUGO, ecard_show_resources, NULL),
        __ATTR(type,     S_IRUGO, ecard_show_type,      NULL),
        __ATTR(vendor,   S_IRUGO, ecard_show_vendor,    NULL),
        __ATTR_NULL,
};


int ecard_request_resources(struct expansion_card *ec)
{
        int i, err = 0;

        for (i = 0; i < ECARD_NUM_RESOURCES; i++) {
                if (ecard_resource_end(ec, i) &&
                    !request_mem_region(ecard_resource_start(ec, i),
                                        ecard_resource_len(ec, i),
                                        ec->dev.driver->name)) {
                        err = -EBUSY;
                        break;
                }
        }

        if (err) {
                while (i--)
                        if (ecard_resource_end(ec, i))
                                release_mem_region(ecard_resource_start(ec, i),
                                                   ecard_resource_len(ec, i));
        }
        return err;
}
EXPORT_SYMBOL(ecard_request_resources);

void ecard_release_resources(struct expansion_card *ec)
{
        int i;

        for (i = 0; i < ECARD_NUM_RESOURCES; i++)
                if (ecard_resource_end(ec, i))
                        release_mem_region(ecard_resource_start(ec, i),
                                           ecard_resource_len(ec, i));
}
EXPORT_SYMBOL(ecard_release_resources);

void ecard_setirq(struct expansion_card *ec, const struct expansion_card_ops *ops, void *irq_data)
{
        ec->irq_data = irq_data;
        barrier();
        ec->ops = ops;
}
EXPORT_SYMBOL(ecard_setirq);

void __iomem *ecardm_iomap(struct expansion_card *ec, unsigned int res,
                           unsigned long offset, unsigned long maxsize)
{
        unsigned long start = ecard_resource_start(ec, res);
        unsigned long end = ecard_resource_end(ec, res);

        if (offset > (end - start))
                return NULL;

        start += offset;
        if (maxsize && end - start > maxsize)
                end = start + maxsize;
        
        return devm_ioremap(&ec->dev, start, end - start);
}
EXPORT_SYMBOL(ecardm_iomap);

/*
 * Probe for an expansion card.
 *
 * If bit 1 of the first byte of the card is set, then the
 * card does not exist.
 */
static int __init
ecard_probe(int slot, card_type_t type)
{
        ecard_t **ecp;
        ecard_t *ec;
        struct ex_ecid cid;
        int i, rc;

        ec = ecard_alloc_card(type, slot);
        if (IS_ERR(ec)) {
                rc = PTR_ERR(ec);
                goto nomem;
        }

        rc = -ENODEV;
        if ((ec->podaddr = __ecard_address(ec, type, ECARD_SYNC)) == 0)
                goto nodev;

        cid.r_zero = 1;
        ecard_readbytes(&cid, ec, 0, 16, 0);
        if (cid.r_zero)
                goto nodev;

        ec->cid.id      = cid.r_id;
        ec->cid.cd      = cid.r_cd;
        ec->cid.is      = cid.r_is;
        ec->cid.w       = cid.r_w;
        ec->cid.manufacturer = ecard_getu16(cid.r_manu);
        ec->cid.product = ecard_getu16(cid.r_prod);
        ec->cid.country = cid.r_country;
        ec->cid.irqmask = cid.r_irqmask;
        ec->cid.irqoff  = ecard_gets24(cid.r_irqoff);
        ec->cid.fiqmask = cid.r_fiqmask;
        ec->cid.fiqoff  = ecard_gets24(cid.r_fiqoff);
        ec->fiqaddr     =
        ec->irqaddr     = (void __iomem *)ioaddr(ec->podaddr);

        if (ec->cid.is) {
                ec->irqmask = ec->cid.irqmask;
                ec->irqaddr += ec->cid.irqoff;
                ec->fiqmask = ec->cid.fiqmask;
                ec->fiqaddr += ec->cid.fiqoff;
        } else {
                ec->irqmask = 1;
                ec->fiqmask = 4;
        }

        for (i = 0; i < ARRAY_SIZE(blacklist); i++)
                if (blacklist[i].manufacturer == ec->cid.manufacturer &&
                    blacklist[i].product == ec->cid.product) {
                        ec->card_desc = blacklist[i].type;
                        break;
                }

        /*
         * hook the interrupt handlers
         */
        if (slot < 8) {
                ec->irq = 32 + slot;
                irq_set_chip_and_handler(ec->irq, &ecard_chip,
                                         handle_level_irq);
                set_irq_flags(ec->irq, IRQF_VALID);
        }

#ifdef IO_EC_MEMC8_BASE
        if (slot == 8)
                ec->irq = 11;
#endif
#ifdef CONFIG_ARCH_RPC
        /* On RiscPC, only first two slots have DMA capability */
        if (slot < 2)
                ec->dma = 2 + slot;
#endif

        for (ecp = &cards; *ecp; ecp = &(*ecp)->next);

        *ecp = ec;
        slot_to_expcard[slot] = ec;

        device_register(&ec->dev);

        return 0;

 nodev:
        ecard_free_card(ec);
 nomem:
        return rc;
}

/*
 * Initialise the expansion card system.
 * Locate all hardware - interrupt management and
 * actual cards.
 */
static int __init ecard_init(void)
{
        struct task_struct *task;
        int slot, irqhw;

        task = kthread_run(ecard_task, NULL, "kecardd");
        if (IS_ERR(task)) {
                printk(KERN_ERR "Ecard: unable to create kernel thread: %ld\n",
                       PTR_ERR(task));
                return PTR_ERR(task);
        }

        printk("Probing expansion cards\n");

        for (slot = 0; slot < 8; slot ++) {
                if (ecard_probe(slot, ECARD_EASI) == -ENODEV)
                        ecard_probe(slot, ECARD_IOC);
        }

#ifdef IO_EC_MEMC8_BASE
        ecard_probe(8, ECARD_IOC);
#endif

        irqhw = ecard_probeirqhw();

        irq_set_chained_handler(IRQ_EXPANSIONCARD,
                                irqhw ? ecard_irqexp_handler : ecard_irq_handler);

        ecard_proc_init();

        return 0;
}

subsys_initcall(ecard_init);

/*
 *      ECARD "bus"
 */
static const struct ecard_id *
ecard_match_device(const struct ecard_id *ids, struct expansion_card *ec)
{
        int i;

        for (i = 0; ids[i].manufacturer != 65535; i++)
                if (ec->cid.manufacturer == ids[i].manufacturer &&
                    ec->cid.product == ids[i].product)
                        return ids + i;

        return NULL;
}

static int ecard_drv_probe(struct device *dev)
{
        struct expansion_card *ec = ECARD_DEV(dev);
        struct ecard_driver *drv = ECARD_DRV(dev->driver);
        const struct ecard_id *id;
        int ret;

        id = ecard_match_device(drv->id_table, ec);

        ec->claimed = 1;
        ret = drv->probe(ec, id);
        if (ret)
                ec->claimed = 0;
        return ret;
}

static int ecard_drv_remove(struct device *dev)
{
        struct expansion_card *ec = ECARD_DEV(dev);
        struct ecard_driver *drv = ECARD_DRV(dev->driver);

        drv->remove(ec);
        ec->claimed = 0;

        /*
         * Restore the default operations.  We ensure that the
         * ops are set before we change the data.
         */
        ec->ops = &ecard_default_ops;
        barrier();
        ec->irq_data = NULL;

        return 0;
}

/*
 * Before rebooting, we must make sure that the expansion card is in a
 * sensible state, so it can be re-detected.  This means that the first
 * page of the ROM must be visible.  We call the expansion cards reset
 * handler, if any.
 */
static void ecard_drv_shutdown(struct device *dev)
{
        struct expansion_card *ec = ECARD_DEV(dev);
        struct ecard_driver *drv = ECARD_DRV(dev->driver);
        struct ecard_request req;

        if (dev->driver) {
                if (drv->shutdown)
                        drv->shutdown(ec);
                ec->claimed = 0;
        }

        /*
         * If this card has a loader, call the reset handler.
         */
        if (ec->loader) {
                req.fn = ecard_task_reset;
                req.ec = ec;
                ecard_call(&req);
        }
}

int ecard_register_driver(struct ecard_driver *drv)
{
        drv->drv.bus = &ecard_bus_type;

        return driver_register(&drv->drv);
}

void ecard_remove_driver(struct ecard_driver *drv)
{
        driver_unregister(&drv->drv);
}

static int ecard_match(struct device *_dev, struct device_driver *_drv)
{
        struct expansion_card *ec = ECARD_DEV(_dev);
        struct ecard_driver *drv = ECARD_DRV(_drv);
        int ret;

        if (drv->id_table) {
                ret = ecard_match_device(drv->id_table, ec) != NULL;
        } else {
                ret = ec->cid.id == drv->id;
        }

        return ret;
}

struct bus_type ecard_bus_type = {
        .name           = "ecard",
        .dev_attrs      = ecard_dev_attrs,
        .match          = ecard_match,
        .probe          = ecard_drv_probe,
        .remove         = ecard_drv_remove,
        .shutdown       = ecard_drv_shutdown,
};

static int ecard_bus_init(void)
{
        return bus_register(&ecard_bus_type);
}

postcore_initcall(ecard_bus_init);

EXPORT_SYMBOL(ecard_readchunk);
EXPORT_SYMBOL(ecard_register_driver);
EXPORT_SYMBOL(ecard_remove_driver);
EXPORT_SYMBOL(ecard_bus_type);